Cam shaft



Dec. 6, 1927; I 1,651,402

R. A. MIDGLEY CAM SHAFT Fi March 29. 192a .2 Sheets-Sheet 1 J v gin-wanker For/6. .df/pfzv,

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, 1,651,402 R. A. MIDGLEY CAM SHAFT Filed March 29. 1926 2 Sheets-Sheet 2 7 v v a 9 a 4 3 I 26 3-minute;

Patented Dec. 6, 1927.

UNITED STATES .ROY A. 'IMlIDGLEY, OF MOUNT DORA, FLORIDA.

CAM SHAFT.

Application filed March as, 192s. Serial No. 98,370.

and the exhaust valves are held continuously open during. continued rotation of the engine crank shaft f' A further object of the invention is the rovision of a novel accelerator pedal control or shifting an engine cam shaft to accomplishv the objects stated above. A still further object is the provision in a cam operated, tappet valve type internal combustion engine, of a novel cam construction and means for shifting position thereof. With these objects in view and such others 2 as will be apparent from the description,

the invention resides in the novel construction, combination and arrangement of parts hereinafter described and claimed, and illustrated in the accompanyin drawings which;

show one practical embodiment of the/invention.

Figure 1 is a perspective of the operating connection between the foot pedal accelerator of an automobile and the longitudinally shiftable cam shaft of the engine, as con structed in accordancewith the principles of the invention Figure 2 is a fragmentary elevation of the cam shaft with the intake valve cam dis- 1 posed thereon and illustrating in dotted lines the shift position ofthe cam and shaft; I Figure 3 is an end elevation of the assembly shown 'in Figure 2;

Figure 4: is an elevation of a portion of the cam shaft with the exhaust valve cam mounted thereon; Q

Figure 5' is a side elevation, partly broken away, illustrating the invention as assembled in relation to the engine.

As shown in Figure 1, the foot pedal constituting the accelerator 10 of an automobile is pivoted intermediate its ends between spaced cars 11 which are integral with and extend laterally from one face of an arm 12,

.mal position of the cam shaft in the which arm is provided on its opposite face with an integral laterally extending shaft 13 whereby it may be mounted for pivotal movement in a supporting member (not shown) carried by the automobile. One end of the arm 12 is formed with an elongated slot 14 through which extends one end of the long arm 15 of a bell crank lever suitably mounted upon some supporting member of the automobile body (not shown). The short arm 16 of the bell crank lever is pivotally connected to a rod 17 having at its end a yoke 18 in swiveled connection with one endof a longitudinally shiftable cam shaft 19 which extends within the engine crank case 20 in the usual manner of such cam shaft constructions. Between the gear casing 21 containing the connecting gearing between the engine crank shaft 22 and the cam shaft 19, a pair of washers 23 and 2 1 are disposed over the projecting portion of the cam shaft for hearing respectively against the yoke 18 and the gear casing 21. Surrounding the shaft between these two washers is a coil expansion spring 25; the purposeof which is to maintain the cam shaft in projected position which is the noroperation of the engine.

By reason of the mounting of the arm 12 which carries the accelerator pedal, when the pedalis moved to one side the arm 12 will be raised in the direction of the arrow carrying up the long arm 15 of the bell crank lever thereby causing the'cam shaft 19to belshifted longitudinally within the engine crank case, against compression of the spring 25; As soon as pressure isrelieved on the accelerator pedal, spring 25 returns the cam shaft to its normal position for the regular alternate timed operation of the engine valves. The accelerator 10 in its normal fuel control operation, rocks in a vertical plane on its pivots between the ears 11, and is'moved sidewise, in a plane at an angle to that of'vits normal movement, to effect shifting of the cam shaft.

As best shown in Figures 2 and 3 the valve rod 26 of the intake valve is operated in the normal position of thecam shaft 19 as shown in full lines, by the usual eccentrio cam 27 which is secured to the cam shaft in the usual manner. One improvement of the present invention consists in providing a cam extension 28 at. one side of the cam 27 

